gambas-source-code/main/gbx/gbx_stream_direct.c

/***************************************************************************

  stream_direct.c

  The direct stream management routines

  (c) 2000-2007 Benoit Minisini <gambas@users.sourceforge.net>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 1, or (at your option)
  any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

***************************************************************************/

#define __STREAM_IMPL_C

#include "gb_common.h"
#include "gb_error.h"
#include "gbx_value.h"
#include "gb_limit.h"

#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

#include "gbx_stream.h"


#define FD (stream->direct.fd)


static int stream_open(STREAM *stream, const char *path, int mode)
{
  int fd;
  struct stat info;
  int fmode;

  if (mode & ST_CREATE)
    fmode = O_CREAT | O_TRUNC;
  else if (mode & ST_APPEND)
    fmode = O_APPEND | O_CREAT;
  else
    fmode = 0;

  switch (mode & ST_MODE)
  {
    case ST_READ: fmode |= O_RDONLY; break;
    case ST_WRITE: fmode |= O_WRONLY; break;
    case ST_READ_WRITE: fmode |= O_RDWR; break;
    default: fmode |= O_RDONLY;
  }

  fd = open(path, fmode, 0666);
  if (fd < 0)
    return TRUE;

  if (fstat(fd, &info) < 0)
    return TRUE;

  if (S_ISDIR(info.st_mode))
  {
    errno = EISDIR;
    return TRUE;
  }

  stream->direct.size = info.st_size;

  FD = fd;
  return FALSE;
}


static int stream_close(STREAM *stream)
{
  if (close(FD) < 0)
    return TRUE;

  FD = -1;
  return FALSE;
}


static int stream_read(STREAM *stream, char *buffer, int len)
{
	return STREAM_read_direct(FD, buffer, len);
}

static int stream_getchar(STREAM *stream, char *buffer)
{
	return read(FD, buffer, 1) <= 0;
}


static int stream_write(STREAM *stream, char *buffer, int len)
{
	return STREAM_write_direct(FD, buffer, len);
}


static int stream_seek(STREAM *stream, int64_t pos, int whence)
{
  return (lseek(FD, pos, whence) < 0);
}


static int stream_tell(STREAM *stream, int64_t *pos)
{
  *pos = lseek(FD, 0, SEEK_CUR);
  return (*pos < 0);
}


static int stream_flush(STREAM *stream)
{
  return FALSE;
}


/*static int stream_eof(STREAM *stream)
{
  int ilen;

  if (STREAM_get_readable(FD, &ilen))
    return TRUE;

  return (ilen == 0);
}*/
#define stream_eof NULL


static int stream_lof(STREAM *stream, int64_t *len)
{
  *len = stream->direct.size;
  return FALSE;
}


static int stream_handle(STREAM *stream)
{
  return FD;
}


DECLARE_STREAM(STREAM_direct);